Recently, development of positional information services in indoor environments is expected due to improvement of accuracy of positioning techniques using base stations and emergence of new positioning techniques such as a WLAN (Wireless Local Area Network) positioning technique for mobile terminals.
As one of the new indoor positioning techniques, attention to an autonomous navigation technique using various sensor information items from an accelerometer sensor, a geomagnetic sensor and others has been drawn. However, there is a problem that errors of measurement using only sensors may be accumulated, and it is important to perform positional correction periodically by using information items other than the sensor information items so as to improve the accuracy. For example, see JP 2007-41143 and JP 2000-97722.